The invention relates generally to optical flame detection.
Previous silicon carbide flame detectors such as described in Brown et al., U.S. Pat. No. 5,589,682, issued Dec. 31, 1996, detect the presence of a flame and measure the intensity of the flame""s photon flux over a wide range of wavelengths. The measured intensity, however, does not always correlate to flame temperature, particularly in multiple flame combustors.
It is therefore seen to be desirable to have a more direct temperature determination technique.
Briefly, in accordance with one embodiment of the present invention, an optical spectrometer for combustion flame temperature determination includes at least two photodetectors positioned for receiving light from a combustion flame and having different overlapping optical bandwidths for producing respective output signals; and a computer for obtaining a difference between a first respective output signal of a first one of the at least two photodetectors with respect to a second respective output signal of a second one of the at least two photodetectors, dividing the difference by one of the first and second respective output signals to obtain a normalized output signal and using the normalized output signal to determine the combustion flame temperature.